Invasive Species

Most plants and animals are delightful to look at and provide an enjoyable connection with nature. However, when non-native plants and animals take up residence in an ecosystem, the results can be harmful and expensive. The introduction of non-native species happens by accident sometimes, and other times it is intentional. Regardless of how it happens, the consequences are often unexpected and may be unpleasant.

One need look no further than the familiar kudzu vine to see what can happen. A perennial vine native to Japan and China, kudzu was first introduced to the United States in 1876 at the U.S. Centennial Exposition in Philadelphia as part of a plant exhibition from Japan. Visitors to the exhibition and the federal government were enamored with kudzu, particularly visitors from the south who began planting kudzu as an ornamental vine to shade porches and courtyards. Then the federal government began promoting kudzu for erosion control. As kudzu began carpeting the southeast and prevented the growth of native plants and trees (primarily by blocking sunlight), the downside of kudzu became apparent. Over time, the federal government changed the classification of kudzu from a permitted cover plant to a common weed and then to a noxious weed.

Today, rail and power companies are engaged in a never-ending expensive battle to clear kudzu from railroad tracks and power lines. And, native vegetation choked out by kudzu can no longer provide food and habitat for native animals. Kudzu has also been a challenge for national parks and forests trying to maintain native plants and trees for visitors. Information about kudzu in this article was compiled from an article on the USDA Forest Service Southern Research Station website at http://www.srs.fs.usda.gov/pubs/ja/ja_blaustein001.pdf and an online manual published by the Southeast Exotic Pest Plant Council at http://www.se-eppc.org/manual/kudzu.html.

Because non-native species can wreak havoc, it is important to discuss them with an expert if you see any or if you are thinking about introducing any. A great starting point is the University of Georgia Center for Invasive Species and Ecosystem Health at http://www.invasive.org/species.cfm. If you think that an invasive species of trees is taking hold in Alpharetta, or an invasive pest is harming trees in Alpharetta, please contact the City of Alpharetta Arborist at (678) 297-6070 or dshostak@alpharetta.ga.us.